Electrical discharge machining (EDM) is a type of machining operation employed for shaping conductive workpieces into geometrically complex parts. Electrical discharge machines are particularly ideal for machining components which have complicated contours or subtle cavities that might be difficult to produce along with other conventional machining equipment. The procedure involves supplying electricity to both the shaping tool along with the workpiece and then bringing the tool into close proximity using the workpiece, that is completely immersed in a dielectric fluid bath. This proximity causes the electrical field intensity between your tool and workpiece to beat the strength of the dielectric fluid, and creates a number of electrical discharges together. These electrical discharges remove material from the workpiece, and also the pattern or shape of material removed is dependent on the form of the tooling electrode. Following the machining operation, the dielectric fluid is replaced between your electrodes. Apart from serving as a dielectric between the two electrodes, the fluid also plays a vital role within the machining process, as it is accustomed to flush away the removed material and cool the machined area. The nature of the process is such that, while materials are being removed from the workpiece; the tooling electrode is also gradually eroded, making periodic replacement necessary.

The electrical discharge machining process is extremely precise and generally utilized in producing components which are typically complex and require extreme accuracy. Additionally, another section of application that EDMs perform above par is in the machining and shaping of hard or exotic materials such as titanium, Hastelloy, Kovar, Inconel, as well as hardened steel. However, the only real caveat using the electrical discharge machining process is that it could be only be combined with conductive materials.

You will find essentially two types of electrical discharge machines, which differ in the type of tooling electrode that they are outfitted with. They are sinker EDMs and wire EDMs. The sinker EDM, also known as a ram EDM uses a shaped tooling electrode to facilitate the machining process. This tooling electrode is created by conventional machining right into a shape that’s specific towards the application it’s employed for as well as an exact reverse from the shape to be machined into the workpiece. The tooling, typically machined from graphite, can be used with an insulating fluid such as oil or other dielectric fluids. This shaped tooling is linked to a power supply and made to approach the workpiece electrode, creating electrical discharges together, which cause erosion within the desired shape. This type of EDM is typically employed for precise machining of complex 3D parts, for example injection molding, die tooling, along with other components that require exceptional accuracy.

The wire EDM, however, is an electrical discharge machine that uses a fine metallic wire, usually made from brass, which provides a cutting electrode to accurately shape intricate, complex aspects of thick metal plates. The wire and workpiece are generally provided with electricity so when the wire approaches the workpiece, electrical discharges occur between them. These discharges remove material from the workpiece inside a shape that resembles a cutting or slicing action. As the wire electrode is eroding along with the workpiece, it’s continuously fed in to the workpiece from a spool to make sure uninterrupted cutting operation. The wire is fed through two guides, typically produced from diamonds, each placed above and below the EDM Manufacturer electrode. These guides are movable on the 2-axis x-y plane and are CNC controlled for cutting. The cutting operation occurs on the workpiece that’s completely immersed in a dielectric fluid bath, normally de-ionized water, which is often used like a coolant and also to flush away the removed material. This machining process is used to chop complex and intricate 2D shapes on thick metal parts, especially aspects of hard and exotic metals such as Inconel and titanium. Some components commonly machined using wire EDMs are stripper plates, custom gears, along with other parts that should be intricately cut out. However, the advent of upper guides and multi-axis freedom of movement within the newer wire EDMs, allows they to chop intricate tapers and transitional shapes too.